Manual telephone system



Feb. 1 1927. 1,615,935

R. c. DAVIS ET AL MANUAL TELEPHONE SYSTEM Filed Dec. 12, 1925lave/vars.- fi/rlmrdffiawls Aayfl. Conway;

PTA

rear: EHQiEh RICHARD G. DAVIS, OF NEW YORK, N. "1.. ANDRQY'D. CONWAY, FBERNARDSVILLE, NEW JERSEY, ASSIGNORS TO BELL TELEPHONE"LZABGRATGRIES,INCORPORATED, OF NEW YQRK, N. Y., A CORPORATION OF NEVJ YO'RIQ MANUALTELEPHONE't'SYSTEM-.

Application filed. December 12, 1925, Serial No. 75,010.

This invention relates to telephone sys tems and more particularly toimprovements in central oflice circuits and rural or magneto lines.

In the copending application Serial No. 49,741, filed August 12 1925, byClarence B. Fowler, is disclosed means suitable for interconnection ofrural lines with common battery lines through standard cord circuits.This system provides means for supervising such connections byintermittently displaying a signal at the central oflice terminal'of arural line when a subscriberon said line operates-his generator;

for displaying a steady signal after the subscriber has ceased tooperate his. generator; for intermittently displaying a. signal when:the subscriber reoperates his generator either as a recall or as adisconnect.

signal. and for extinguishing the signal when the operator at thecentral office makes connection with this subscribers line.

In systems of this type it is not ordinarily desirable to multiple thelinesignals to any positions'other than the positions especiallyassigned for answering rural line calls that is they are not m-ultipledto positions where common battery linesare multipled as the method ofsupervisingis not in accordance with the standard method.

It is an object of this invention to -improve the supervisory signalingfor rural.

lines-so that these lines may be multipled at the switchboards in thesame manner as eommo-nrbattery lines.

To attain thisand other objects of the invention there is-provided inaccordance with one feature. thereof. means whereby the line lamps ofrural lines fnnctionin the same manner to supervise a connection as thelanrps of lines of the common battery type. That is in accordancewiththis invention the line lamps will lightsteadily when a connection isdesired and be extinguished when the call is answered;

The arrangement. is such that when a rural-subscriber actuates hisgenerator to call a central oficc operator a condition is set up in thecircuit at the central oflice that causes the line lamps to lightsteadily when the subscriber ceases to operate his generator.Consequently when one rural subscriber calls another on the same linethe line-lamps at the central office will be ,mon circuit equipment atthe central ofiice embodying. this invention isalsoshown as well asmultiple packs 1, 2 and'S with corresponding. line lamps 4, 5 and 6shown teases respectivelyat.operators positions E, F and G from. whichconnections desired by the rural subscribers on this line may beanswered or at which connections to these rural subscribers may be made.The answeringplug. and aportion of an-ordinary standard cord circuit forestablishing. ,-c0nncctionswithithis rural line have also been shown.

To clearly bring. out the various features of this invention,descriptions of the functions of the circuits shown, will be made;first, when a call is incoming over the line to the exchange and second,when a call is outgoingover the line from tae exchange.

Considering ,thatthe. rural subscriber at A operates the generator toestablish a connection current. from, the generator will operate thealternatingv current responsive relay- 10. Relay 10 in operating closesa circuit for relay 11 as follows: battery, winding of relay 11,armature and back contact of relay 12, inner upper armature andfrontcontact of relay 10 to ground. Relay 11 in operating provides a lockingcircuit for itself from battery through its winding, armature and backcontact of relay 12, inner right handarmature and front contactof relay11 to ground. The operationof relay 11 also prepares a circuit for thelighting of lamps 4, 5 and 6 when the subscriber ceases to operate hisgenerator, thatis when relay 10 is released a circuit is completed forlighting these lamps as follows: from battery through lamps 4, 5 and 6in parallel, inner left hand armature and front contact of relay 11,right hand armature and back contact of relay 10 to ground.

It should be noted that if one rural subscriber decides to call anotherrural subscriber on the same line, relay 10 will be operated each timethe calling rural subscriber operates his generator to ring the code ofthe wanted rural subscriber. When relay 1O first opera es, relay 11 isoperated and locked while lamps 1, 5 and 6 light on the first release ofrelay 10. At succeeding operations and releases of relay 10, lamps &, 5and 6 will be alternately extinguished and lighted. An operator at thecentral ofiice noticing the flashing of the lamps in accordance with thecode used will, as soon as the lamps finally remain lighted steadily,insert her plug such as 15, in a jack such as one to extinguish thelamps 4L, 5 and 6 and immediately thereafter remove it. On the insertionof the plug into the jack a circuit will be established from batterythrough the lower right hand winding of repeating coil 16, supervisoryrelay 17, terminals of plug 15 and jack, 1, make-before'break contactsof relay 18, winding of relay 12, retardation coil 19, tip terminals ofjack 1 and plug 15, upper right handwinding of repeat coil 16 to ground.This causes the operation of relay 12 which opens the connection throughits armature and back contact to cause the release of relay 11.

If the line lamps l, 5 and 6 do not flash but light steadily itindicates that a rural subscriber is calling and the operator willanswer the call by inserting her plug 15 into jack 1 and this causes theextinguishing of lamps 4, 5 and 6 as previously described. The operationof relay 12 preparesa circuit, for the subsequent operation of relay 18as will be hereinafter described. It should be noted that with theanswering plug 15 in jack 1,

relay 17 will operate in the previously traced circuit through the tipand ring conductors and thus prevent the operation of the supervisorylamp 20 as is the usual practice.

The operator will now actuate her talking key in the usual manner toconnect her telephone set to the cord and the rural subscriber will givethe operator the desired number so that connection may be extended tothe wanted subscriber and conversation carried on in the manner wellknown in the art.

After the conversation is finished the rural subscriber desiring torelease the connection operates his generator thereby causing theoperation of relay 10. It should be noted that in this case a connectionis established through the operation of relay 12, for relay 18. Thiscircuit may be traced as follows: battery, winding of relay 18, armatureand front contact of relay 12, left hand armature and front contact ofrelay 10 to ground. Relay 18 in operating provides a locking circuit foritself under control of relay 12 as follows: battery, winding of relay18, armature and front contact of relay 12, right hand armature andfront contact of relay 18 to ground. The operation of relay 18, however,opens the circuit including the windings of relays 12 and 17 as itsmakebefore-break contacts, so that relay 17 will now release while relay12 will remain operated from battery, left hand armature and frontcontact of relay 18, winding of relay 12 over the tip conductors toground at the upper right hand winding of repeating coil 16. The releaseof relay 17 causes the supervisory lamp 20 to light to call theoperators attention to the fact that the rural subscriber has rung off.The operator now removes plug 15 from jack 1, and relays 17 and 18 arereturned to normal position while lamp 20 is extinguished.

If the rural subscriber instead of ringing off has decided to recall theoperator, he will operate his generator in the same manner. After theoperator has removed plug 15 from jack 1 and relay 18 has released, ifthe subscriber continues or again operates his generator, relay 11 willoperate and on the ceasing of the ringing, lamps 4t, 5 and 6 will belighted as hereinbefore described.

If a connection is desired to a rural subscriber the operator willinsert her plug 15 in jack 1 and in this case relay 12 will operate aspreviously traced. The operation of relay 12 in this case performs nouse ful function but the operator now actuates her usual ringing key 25which causes the release of relay 12 and the transmission of ringingcurrent over the line conductors. This operates the alternating currentresponsive relay 10 which causes the operation of relay 11. This latterrelay in operating closes a path for the ringing current to facilitatethe ringing of the wanted subscriber as follows: from the source ofalternating current, key 25, over the ring terminals of plug 15 and jack1, resistance 26, outer left hand armature and front contact of relay 11to the ring conductor of the line around the condenser 27 through thebell of the wanted subscribers line over the tip conductor of the linethrough resistance 28 the outer right hand armature andfront contact ofrelay 11, around the condenser 29, tip terminals of jack 1 and plug 15to ground at key 25. Relay 10 is released on the restoration of the key25 to normal and relay 12 is reoperated causing the release of relay 11.The circuit is now in condition for conversation and for receiving ofringing off signals from the connected rural subscriber.

What is claimed is:

1. In a telephone system, a telephone line, a signal associatedtherewith, a source of current associated with said line, a secondsource of current, means responsive to current from said first mentionedsource for actuating said signal, said means actuated on the applicationof said current and actuating said signal upon the termination of theapplication, and means for restoring said signal to normal conditionresponsive to the application of current to said line from said secondsource.

2. In a telephone system, a telephone line, a signal associatedtherewith, a source of current associated with said line, a cordcircuit, a signal associated therewith, a source of current associatedwith said cord circuit, means responsive to current from said firstmentioned source for actuating said first mentioned signal, said meansoperating-on the application of said current and actuating said signalupon the termination of the application, means for restoring said signalto normal condition responsive to the application of current from saidsecond mentioned source on the connection of thecord circuit to saidline, and means for operating said second mentioned signal after saidcord circuit has heenassociated with said line responsive to theapplication of current from said first mentioned source to said line.

In Witness whereof, We hereunto subscribe our names this 1st day ofDecember A. D., 1925.

RICHARD C. DAVIS. ROY D. CONWAY.

